This report describes a class of software tools that check formal requirements specifications for consistency with a requirements model. The model, which describes properties of requirements specifications based on the SCR (Software Cost Reduction) approach to requirements, is summarized. Two experiments are described in which condition tables and mode transition tables in an updated version of the A-7 requirements document were checked for selected properties using tools we developed. The significant number of errors found by the tools is summarized. Tool-based techniques and manual techniques for performing consistency checks are compared, and several additional consistency checks, derived from the formal model, are identified. Our work is compared with related work by Parnas and SRI concerning the automated checking of tabular specifications. Conclusions are presented concerning the utility, cost, and scalability of tool-based consistency checking.